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IAUC 6841: 1998V; 1998S

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                                                 Circular No. 6841
Central Bureau for Astronomical Telegrams
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
URL http://cfa-www.harvard.edu/iau/cbat.html
Phone 617-495-7244/7440/7444 (for emergency use only)

     G. M. Hurst, Basingstoke, England, reports the discovery of an
apparent supernova (mag about 16) by Mark Armstrong, Rolvenden, on
an unfiltered CCD image obtained on Mar. 10.219 UT with a 0.20-m
reflector in the course of the U.K. Nova/Supernova Patrol.  An
image obtained on Mar. 12.115 by Armstrong yields mag 15.5 and the
following position:  R.A. = 18h22m37s.40, Decl. = +15o42'08".4
(equinox 2000.0), which is about 30" northwest of the center of NGC
6627.  The object is not present in the Vickers CCD atlas or the
Palomar Sky Survey, nor does it appear on earlier U.K. patrol
images obtained during 1997 July 28-Oct. 21.  T. Boles,
Wellingborough, England, imaged the galaxy on Mar. 12.156, also
finding SN 1998V near mag 15.5 (unfiltered CCD).  Hurst further
reports that there is no star present in the USNO A1.0 catalogue to
mag 19.
     S. Nakano, Sumoto, Japan, forwards the following precise
position end figures and magnitude for SN 1998V, measured by Y.
Kushida from a CCD image taken by R. Kushida on Mar. 13.75 UT with
a 0.40-m reflector at Yatsugatake South Base Observatory:  37s.40,
07".7, V = 15.1.

     Y. L. Qiu, Beijing Astronomical Observatory (BAO), writes:
"The low-dispersion spectra taken with 2-m telescope at Xinglong
Station by L. Cao, Y. L. Qiu, and Q. Y. Qiao on Mar. 7.7 and 12.7
UT show that the spectral evolution of SN 1998S is peculiar.  The
spectrum obtained on Mar. 12 displayed a blue continuum,
superimposed by weak Balmer lines, H-alpha, H-beta, H-delta, and
H-gamma.  The features near 467 nm (He II and permitted N III/C
III, as reported on IAUC 6832) in the spectrum of Mar. 7 nearly
disappeared by Mar. 12.  The profiles of H-alpha and H-beta in the
spectrum of Mar. 12 change to be asymmetric, and the blue wings
become steeper.  The equivalent widths of H-alpha and H-beta are
-0.83 nm, and -0.24 nm, respectively, compared to -3.2 nm and -1.3
nm on Mar. 7.  The full width at the base of H-alpha is 7.4 nm,
implying an expansion velocity of 3380 km/s."
     Visual magnitude estimates:  Mar. 12.75 UT, 12.5 (L. Kiss,
Szeged, Hungary); 13.22, 12.2 (R. Keen, Mt. Thorodin, CO; T UMa
AAVSO chart); 14.799, 12.1 (K. Hornoch, Lelekovice, Czech
Republic; GSC stars).

                      (C) Copyright 1998 CBAT
1998 March 14                  (6841)            Daniel W. E. Green

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